Conventionally, there are known stators of rotating electric machines which include an annular stator core and a stator coil. The stator core has a plurality of slots arranged in the circumferential direction at predetermined intervals. The stator coil is formed of a plurality of electric conductor wires mounted on the stator core. In addition, each of the electric conductor wires has a plurality of in-slot portions received in the slots of the stator core and a plurality of turn portions that connect, on the outside of the slots, adjacent pairs of the in-slot portions.
Moreover, each of the electric conductor wires forming the stator coil may be made up of one wave-shaped continuous electric conductor wire that includes a plurality of in-slot portions and a plurality of turn portions. Otherwise, each of the electric conductor wires may be made up of a plurality of substantially U-shaped electric conductor segments each of which includes a pair of straight portions and a turn portion that connects a pair of ends of the straight portions. More specifically, each of the electric conductor wires may be formed by connecting predetermined pairs of open end portions of the electric conductor segments on one axial side of the stator core. In addition, in Patent Document 1, there is disclosed a method of forming the substantially U-shaped electric conductor segments.
The stator coil has a pair of coil end parts that respectively protrude axially outward from a pair of axial end faces of the stator core. In addition, at each of the coil end parts, there are stacked, in a radial direction of the stator core, the turn portions of the electric conductor wires or connecting portions of the electric conductor wires which are formed by connecting the predetermined pairs of open end portions of the electric conductor segments.